Apparatus for reacting liquids



July 2, 1968 A. WURBS APPARATUS FOR REACTING LIQUIDS 2 Sheets-Sheet 1 Filed ,Jan.

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I INVENTOR. I A/a/fi! United States Patent 3,390,964 APPARATUS FOR REACTING LIQUIDS Alfred Wurbs, 22 Gerhart Hauptmann Str., Heidelberg, Germany Filed Jan. 3, 1964, Ser. No. 335,465 Claims priority, application Gezm'any, Sept. 13, 1963,

6 Claims. oi. 23-285) ABSTRACT OF THE DISCLOSURE The present invention relates to a process and apparatus for reacting liquids which are of different specific gravities.

Where a pair of liquids are of different specific gravities and are placed in a suitable reaction vessel, the lighter liquid will of course rest on the heavier liquid so that there will be between the liquids an interface at which the liquids react with each other. For many purposes the area of contact between such liquids at their interface is insuflicient to provide an output of sufficient magnitude.

It is therefore a primary object of the present invention to provide a process and apparatus capable of increasing the area of contact between two liquids of different specific gravities far beyond the area of the interface between two such liquids in a reaction vessel.

Another object of the present invention is to provide a process and apparatus enabling one of the reaction liquids to be continuously transported into and released into the other liquid to react therewith.

A further object of the present invention is to provide a process and apparatus capable of maintaining between the liquids, at areas different from the interface therebetween, a substantially laminar flow.

An additional object of the present invention is to provide a process and apparatus where the area of contact between two liquids of different specific gravities is not only increased beyond the area of the interface between these liquids in a reaction vessel, but also where the liquids will move in =countercurrent to each other at areas beyond the interface therebetween.

A still further object of the present invention is to provide an apparatus capable of accomplishing the above objects while at the same time being inexpensive, simple, rugged, and reliable in operation.

Also, it is an object of the present invention to provide a process and apparatus capable of fulfilling the above objects while at the same time being particularly suitable for the production of sodium dithionite.

With the above objects in view, the invention includes, in an apparatus for reacting two liquids of different specific gravities, a vessel in which the liquids are located with the lighter one resting on the heavier one and with the liquids having between themselves an interface of a given area. In accordance with the present invention, there is located in the vessel a means which will increase the area of contact between the liquids beyond the area of the interface, and this means includes a rotary disc means extending into both liquids, receiving part of the lighter liquid, transporting, during rotation of the disc means, part of the lighter liquid into the heavier liquid,

3,399,964 Patented July 2, 1968 ICC and at its portion which is in the heavier liquid having the latter displace the lighter liquid out of the disc means to react with the heavier liquid at an area beyond the interface.

Also, in accordance with the above objects, the present invention includes a process involving the steps of placing in a vessel a sodium amalgam and a sulfite and bisulfite containing aqueous solution on the amalgam to form therewith an interface at which the liquids can react. In accordance with the process of the invention, part of the aqueous solution is continuously transported into the amalgam to react therewith at areas beyond the interface, so that a highly concentrated sodium dithionite solution will be formed at a rapid rate.

The novel features which are considered as characteristic for the invention are set forth in particular inthe appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIG. 1 is a longitudinal sectional illustration of one possible apparatus according to the present invention;

FIG. 2 is a transverse sectional view of the structure of FIG. 1 taken along line 2-2 of FIG. 1;

FIG. 3 is a transverse sectional view of the structure of FIG. 1 taken along line 44 of FIG. 1;

FIG. 4 is a transverse sectional view of the structure of FIG. 1 taken along 44 of FIG. 1;

FIG. 5 is a partly broken away side elevation of one possible disc 'means according to the present invention;

FIG. 6 is a section of the structure of FIG. 5 taken along line 6-6 of FIG. 5;

FIG. 7 is a side elevation of another embodiment of a disc means according to the invention; and

FIG. 8 is a section of FIG. 7 taken along line 88.

Referring to FIG. 1, the reaction vessel 1 illustrated therein is in the form of an elongated cylindrical container which is closed throughout and to which and from which fluids flow through suitable conduits as described below. Suitable bearings are connected to the end walls of the vessel 1 to support for rotary movement a shaft 2 which extends parallel to and is located below the axis of the cylindrical vessel 1. The shaft 2 is rotated about its axis by a suitable drive means connected to the end portion 3 of the shaft 2.

As will be apparent from the description which follows, a pair of liquids of different specific gravities are adapted to be located in the vessel 1 to react therein, and the shaft 2 forms part of a means for increasing the area of contact between these liquids beyond the area of the interface resulting from the resting of the lighter liquid on the heavier liquid. This means includes, in addition to the shaft 2, a disc means which in the illustrated example is made up of a plurality of discs 4 fixed to and distributed along the shaft 2 for rotation therewith. As is apparent from FIG. 1, the discs 4 are arranged in groups which are distributed along the shaft with the space between the discs of each group substantially smaller than the distance between successive groups. It has been found from experience as well as theory that a general rule of thumb which may be followed is to make the distance between successive groups of discs substantially equal to the total of the distances between the discs of one group. In the illustrated example it will be seen that each group is made up of six discs 4 spaced from each other by spacers 5. The left end disc is fixed in any suitable way rigidly with the shaft 2, and all of the other discs are slipped onto the shaft. Each disc is formed, in the illustrated example, with a set of three openings, and these 3 openings of the several discs are aligned with each other so that three rods 7 can pass through the series of aligned openings of the discs with the spacers 5 placed on the rods 7 between the discs of the several groups as illustrated in FIG. 1. The rods 7 have enlarged head ends engaging the left face of the left end disc of FIG. 1 and threaded ends receiving nuts and extending beyond the right end disc of FIG. 1, so that in this way the entire assembly of discs can be tightly drawn together for rotation with the shaft 2. Between the several groups of discs are located a plurality of transporting means 6 for a purpose described below. As may be seen from FIG. 4, each transporting means 6 has a central hub portion through which the shaft 2 passes and three equidistantly spaced arms radiating from the hub portion and formed at their outer ends with openings through which the rods 7 pass. FIG. 3 illustrates the circumferential distribution of the rods 7 and spacers 5 for each disc 4.

As is illustrated in FIG. 2, there is located in the vessel 1 liquids and 21 of different specific gravities, the liquid 20 being lighter than and resting on the liquid 21 to provide between the liquids the interface 22 at which the liquids can react with each other, the reaction being such that, for example, a substance carried by the heavier liquid 21 is given up to the lighter liquid 20. The rotary disc means of the invention greatly increases the area of contact between the liquids 2G and 21, beyond the area of the interface 22, and for this purpose the disc means may have, for example, the structure shown in FIGS. 5 and 6 or the structure shown in FIGS. 7 and 8.

As may be seen from FIGS. 5 and 6, each disc 4a has a hollow interior 23 defined between spaced side walls 24 and 25 of each disc 4a. These side walls are formed with apertures 26, and in addition the side walls have integrally formed therewith ribs 27 which form partitions dividing the hollow interior 23 into pockets 28, the configuration of the ribs 27 leaving at the outer periphery of the disc 4a openings 29 communicating with the interior and exterior of the disc.

With this construction, it will be seen that the liquids 2t) and 21 will enter into the pockets 23 at the portions of the discs which are located in these liquids. During rotation of each disc 4a in a clockwise direction, as viewed in FIG. 5, the lighter liquid 20 will be transported down into the heavier liquid 21 which displaces the lighter liquid out of the pockets 28 and the lighter liquid when thus displaced flows through the apertures 26 along the exterior surface of the disc to provide an extremely large area of contact between the liquids far beyond the area of the interface 22.

With the embodiment which is shown in FIGS. 7 and 8 each disc 4b is in the form of a rigid member 30 formed in its opposed faces with a pair of annular recesses 31 in which is located a suitable absorbent material 32. This material 32 is chosen so that it does not react with the liquids, and the same is of course true of all of the materials of the vessel, the shaft, the discs, and the other elements. For example, the material 32 may be felt or a suitable foam plastic fixed to the body 30 as by being glued thereto also with an adhesive which does not react with the liquids. With this construction the lighter liquid will be absorbed into the material 32 at the portions thereof located in the lighter liquid, and during rotation of each disc 4b, the lighter liquid will again be transported into the heavier liquid to be displaced by the latter out of the absorbent material into the heavier liquid to greatly increase the area of contact between the liquids.

With the structure of the invention, not only is the area of contact between the liquids greatly increased beyond the area of the interface therebetween while maintaining a substantially laminar flow between the liquids so that they are in surface-to-surface contact, as distinguished from small droplets of one liquid surrounded by the other liquid, but in addition the structure of the invention will produce a substantially counter-current flow relationship between the liquids. This result is brought about by the plurality of transporting means 6 and the distribution of the discs in groups as shown in FIG. 1. Assuming that the discs rotate in a clockwise direc ion, as shown by the arrow in FIG. 4, it will be seen that as each arm of the transporting means 6 turns through the heavier liquid 21, this heavier liquid is transported by each arm from the right side to the left side of the vessel 1, as viewed in FIGS. 2 and 4. As a result, the level of the heavier liquid will tend to be higher on the left side of the vessel 1 than on the right side thereof. The heavier liquid which is transported in this way will of course automatically seek to return to the lower level at the right side of the vessel. With the construction shown the liquid which is transported to the left side of the vessel by the rotating means 6 flows at the left side of the vessel longitudinally therealong between the several transporting means 6 and thus longitudinally along the several groups of discs 4 to enter into the spaces between the disc 4 of each group, and this part of the heavier liquid necessarily flows through the spaces between the discs 4 of each group from the left side toward the right side of the ves sel, as viewed in FIGS. 2 and 4. Inasmuch as the discs 4 turn with the transportation means 6 and shaft 2, the lower portions of the discs 4 move from the right side toward the left side of the vessel and the lighter liquid carried by the discs into the heavier liquid also moves with the discs from the right side toward the left side of the discs, so that the lighter liquid while displaced by the heavier liquid also moves in countercurrent thereto in the spaces between the discs 4 of each group, thus enhancing the reaction between the liquids.

The heavier liquid 21 may, for example, carry a substance which is given up to the lighter liquid 20 as a result of the reaction there'between. A weir 13 is carried by the vessel 1 at the lower right portion thereof, as viewed in FIG. 1, and the heavier liquid 21 continuously fiown over the upper edge of the weir 13 to be conveyed out of the vessel 1 by a suitable unillustrated conduit, so that the weir 13 controls the level of the heavier liquid. This heavier liquid is introduced into the vessel through conduit 8 (FIGS. 1 and 2) which is at the elevation of the heavier liquid and which is apertured at its portion within the vessel 1, so that the heavier liquid discharges from the conduit 8 into the vessel 1. Between the conduit which receives the heavier liquid flowing over the weir 13 and the conduits 8 at the exterior of the vessel 1 is located a suitable structure for replenishing the heavier liquid with the substance which is given up to the lighter liquid, so that in this way a heavier liquid with a high concentration of this substance can be continuously introduced into the vessel 1 while the heavier liquid with only a small concentration of this substance flows over the weir 13.

A second weir 11 is located in the vessel 1 at the right portion thereof, as viewed in FIG. 1, and this second weir is inverted, as indicated in FIG. 1. The second liquid is introduced into the vessel through the conduit it) which passes fluid-tightly through an upper portion of the vessel and has in the interior thereof along the upper wall portion thereof an elongated tubular portion suitably perforated so that the lighter liquid 20 will be sprayed downwardly into the vessel. The level of the lighter liquid 20 when it is originally introduced rises until it engages the lower edge of the inverted weir 11, and then on the left side of this weir, the lighter liquid 20 continues to rise trapping a gas in the vessel 1 above the lighter liquid 20 between the latter and the upper wall portion of the vessel as well as between the left end wall thereof, as viewed in FIG. 1, and the weir 11, and the level of the lighter liquid continues to rise until there is an equiiibrium in the pressure between the li hter liquid and the gas thereabove on the left side of the weir 11 in FIG. 1. On the right side of the weir 11 in FIG. 1, the lighter liquid can continue to rise until it flows out through the conduit 1' which communicates with the interior of the vessel i at an upper portion thereof at the right side of the weir 11, as viewed in FIG. 1. This liquid which flows out through the conduit 12 will of course be enriched with the reaction products of the liquids 20 and 21. The liquid introduced to the conduit to flow therethrough into the vessel 1 is of course to be enriched with this substance and may have a very low concentration thereof. A reaction may also take place with the gas above the lighter liquid, this gas, for example, bubbling through the lighter liquid around the weir 11 to be absorbed at least partly into the lighter liquid, and a conduit 9 (FIG. 2) extends into the upper portion of the vessel 1 where the gas is located to replenish the gas.

Inasmuch as a cooling apparatus cannot be accommodated in the interior of the above-described structure, cooling can take place in a conventional manner at the exterior of the above-described structure. For example, an unillustrated conduit which communicates with the space which is just to the right of the weir 11 in FIG. 1 can continuously direct the lighter liquid to a heat exchanger of any suitable type in which the lighter liquid is cooled to the desired degree, and this liquid upon leaving such a heat exchanger can simply be reintroduced back through the spray tube 10 into the reactor.

In order to obtain highly concentrated solutions, several of the above-described reactors are connected in series in such a way that the solution fed to the first of the series of reactors flows out of the conduit 12 thereof into the next of the series of reactors, and so on, so that in this way there will be obtained from the last reactor of the series a highly concentrated solution.

Example The above-described process and apparatus is particularly suitable for the production of sodium dithionite. For this purpose the heavier liquid 21 is a sodium amalgam while the lighter liquid 21) is a sulfite and bisulfite containing aqueous solution, and between the liquids takes place the reaction:

Sulfur dioxide is introduced through the conduit 9 into the gas space, and sodium dithionite is produced from the sodium amalgam and sulfur dioxide in the presence of the sulfite and bisulfite containing aqueous solution. The process and apparatus of the present invention produces a very high yield as compared to conventional processes and apparatus.

All of the parts which come into contact with the reacting materials are made of electrically nonconductive material which will not react therewith. The vessel 1 may be made of a plastic such as polyvinyl chloride or polystyrene, which may be reinforced with glass fibers, or, if desired, the vessel may be made of a metal such as iron which is coated with such a plastic. The discs rotate at a relatively slow speed and enter into all three phases, namely the two heavier and lighter liquids and the gas. The discs are made of a suitable ceramic or plastic material, such as the above plastics, and in the embodiment of FIGS. 7 and 8 the material 32 may be in the form of a polyvinyl chloride or polystyrene foam plastic. The shaft 2 may be made of a metal covered with rubber or either of the above plastics, and of course the spacers 5, the transporting means 6, and the rods 7 as well as the nuts carried thereby, and of course the weirs and conduits are all made ofsimilar plastics or metals coated therewith, so that all of the parts are not electrically conductive.

If desired the discs may simply be made of highly porous elements whose pores receive the liquids. Thus, the discs become covered with a film of the aqueous solution which clings to the discs and turns therewith into the amalgam so as to form in the amalgam a diffusion layer of large area within which the reaction components (HSO from the aqueous solution and Na from the amalgam) takes place in accordance with the above reaction forming S 0 Of course, if desired, the exterior surfaces of the discs maybe formed with grooves or depressions of any desired configuration. The discs may each have a thickness of 48 mm., and the spacing between the discs of each group may be on the order of 1-4 mm., with each group containing, for example, from 6 to 12 discs, so that there is a considerable economy in the distribution of the mercury.

The amalgam which flows over the weir 13 has very little sodium, and this amalgam is passed, after leaving the vessel 1, through a suitable electrolytic cell well known in the art wherein it becomes enriched with sodium before being reintroduced into the vessel 1 through the conduits 8. The length of the conduits 8 and the apertures are such that the fresh amalgam is introduced in the vessel 1 uniformly along the entire length thereof to the left of the weir 13 in FIG. 1.

As the amalgam flows through the narrow spaces between the discs 4, the amalgam gives up the sodium at the diffusion layer between the amalgam and the aqueous solution clinging to the surfaces of the discs, thus forming sodium dithionite according to the above reaction.

The above reaction takes place according to the overall reaction:

which can be broken down into the reactions:

and the required sulfur dioxide is introduced through the conduit 9 which is also provided in the vessel 1 with apertures through which the sulfur dioxide flows into the vessel.

The above process is continuous and there is continuously introduced a sulfite and bisulfite containing aqueous solution through the conduit 10, the solution which leaves through the conduit 12 of course being enriched with dithionite.

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of reaction apparatus and processes differing from the types described above.

While the invention has been illustrated and described as embodied in liquid reacting processes and apparatus, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any 'way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention and, therefore, such adaptations should and are intended to 'be comprehended within the meaning and range of equivalence of the following claims What is claimed as new and desired to be secured by Letters Patent is:

1. In an apparatus for reacting a pair of liquids of different specific gravities, in combination, a vessel having a substantially horizontal axis and being adapted to contain the liquids with the lighter one resting on the heavier one and with the liquids having between themselves an interface of a given area where the liquids react; a rotary shaft extending parallel to said axis through said vessel; a plurality of groups of disc means carried by said shaft for rotation therewith with the disc means of each group spaced at relatively small distances from each other along the shaft with the space between the disc means of each group free of stationary members, and the plurality of groups of disc means being spaced from each other by distances larger than the distance between any two successive disc means of any one group, each disc means extending into both liquids to receive some of the lighter liquid and to transport it during rotation into the heavier liquid to be displaced from the disc means by the heavier liquid so as to increase the area of contact between the liquids beyond the area of said interface; and means carried by said shaft between said groups of discs for rotation with said shaft and for advancing the heavier liquid in one direction transverse to said axis during rotation of said shaft and discs, whereby the heavier liquid will automatically return in the opposite direction in the smaller spaces between the plurality of disc means of each group in only an area of contact beyond that of said interface but also a countercurrent flow between the liquids.

2. In an apparatus as recited in claim 1, said means between said groups of disc means for transporting the heavier liquid in said one direction including between each pair of successive groups of disc means a substantially star-shaped member having a central portion fixed to said shaft and a plurality of arms radiating from said central portion and extending in axial direction over a distance equal to the spacing between the respective pair of successive groups of disc means.

3. In anapparatus for reacting a pair of liquids of different specific gravities, in combination, an elongated substantially cylindrical vessel having a substantially horizontal axis and being adapted to contain the liquids with the lighter one resting on the heavier one and with the liquids having between themselves an interface of a given area where the liquids can react; an elongated rotary shaft extending along the interior of the vessel parallel to the axis thereof; a plurality of groups of disc means carried by said shaft for rotation therewith, the plurality of discs in each group being spaced from each other by a distance substantially smaller than the distance between said groups with the space between the disc means of each group free of stationary members, and each disc means extending into both liquids to receive part of the lighter liquid and to transport it during rotation of the disc means into the heavier liquid to be displaced by the latter out of the disc means so as to increase the area of contact between the liquids beyond the area of said interface; and transporting means carried by said shaft and extending in axial direction between said groups of disc means for laterally transporting the heavier liquid in one direction in said vessel during rotation of said shaft, whereby the heavier liquid will automatically flow in the reverse direction across the vessel in the spaces between the plurality of disc means of each group, to provide a countercurrent flow between the liquids in the spaces between the plurality of disc means of each group.

4. In an apparatus as recited in claim 3, said disc means including at least one disc having a hollow interior and a pair of spaced side walls formed with openings passing therethrough, said disc having between said side walls partitions dividing the interior of the disc into pockets which communicate with said openings and which are distributed between the liquids so that some of said pockets are in one liquid and some of said pockets are in the other liquid, whereby during rotation of the disc the lighter liquid which enters into some of said pockets will be transported in said ockets into the heavier liquid to be displaced out of the pockets by the heavier liquid.

5. In an apparatus as recited in claim 3, said disc means including at least one disc composed of a rigid body carrying an absorbent material which extends into both liquids for absorbing the lighter liquid at the part of the material which is located in the lighter liquid and trans porting the thus absorbed lighter liquid during rotation of the disc into the heavier liquid to be displaced out of the material by the heavier liquid.

6. In an apparatus for reacting a pair of liquids of dif ferent specific gravities, in combination, an elongated substantially cylindrical vessel having a substantially horizontal axis and being adapted to contain the pair of liquids with the lighter one resting on the heavier one and with the liquids having between themselves a reacting interface of a given area; an elongated rotary shaft extending along the interior of the vessel parallel to the axis thereof; disc means carried by said shaft for rotation therewith and extending into both liquids for receiving some of the lighter liquid and transporting it into the heavier liquid to be displaced from the disc means for the heavier liquid so as to increase the area of contact between the liquids beyond the area of said interface; conduit means communicating with the interior of the vessel at the elevation of the heavier liquid for introducing into the vessel additional heavier liquid carrying a substance which leaves the heavier liquid and goes into the lighter liquid during reaction between said liquids; a first weir in said vessel over which the heavier liquid flows out of said vessel for maintaining the level of the heavier liquid in said vessel; a second weir extending into said vessel and controlling the elevation of the top surface of the lighter liquid in said vessel, the lighter liquid flowing past the second weir out of the vessel after being enriched with the substance from the heavier liquid, said second weir being inverted and having a lower edge which controls the elevation of said lighter liquid and said second weir trapping a gas in said vessel between the top thereof and said lighter liquid; means communicating with an upper portion of said vessel for introducing into the same said lighter liquid to be enriched with the substance from said heavier liquid; and means communicating with the space in said vessel above said lighter liquid for introducing a gas into said space.

References Cited UNITED STATES PATENTS 2,012,508 8/1935 Halstead 26l92 X 2,084,651 6/1937 Mecklenberg et al. 23-116 2,169,338 8/1939 Ditto 23285 X 2,210,354 8/1940 Bates 26192 X 2,537,211 1/1951 Cox 26192 OSCAR R. VERTIZ, Primary Examiner. E. C. THOMAS, Assistant Examiner. 

